timezoneimpl.java

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    case DOW_LE_DOM_MODE:
      ruleDayOfMonth = ruleDay -
        (49 - ruleDayOfWeek + ruleDay + dayOfWeek - dayOfMonth) % 7;
      // Note at this point ruleDayOfMonth may be <1, although it will
      // be >=1 for well-formed rules.
      break;
    }

    if (dayOfMonth < ruleDayOfMonth) return -1;
    else if (dayOfMonth > ruleDayOfMonth) return 1;

    if (millis < ruleMillis) return -1;
    else if (millis > ruleMillis) return 1;
    else return 0;
  }

  /**
   * Gets the GMT offset for this time zone.
   */
  public int getRawOffset() {
    // The given date will be taken into account while
    // we have the historical time zone data in place.
    return rawOffset;
  }

  /**
   * Queries if this time zone uses Daylight Savings Time.
   */
  public boolean useDaylightTime() {
    return useDaylight;
  }

  /**
   * Gets the ID of this time zone.
   * @return the ID of this time zone.
   */
  public String getID() {
    return ID;
  }

  /**
   * Gets the <code>TimeZone</code> for the given ID.
   * @param ID the ID for a <code>TimeZone</code>, either an abbreviation such as
   * "GMT", or a full name such as "America/Los_Angeles".
   * <p> The only time zone ID that is required to be supported is "GMT",
   * though typically, the timezones for the regions where the device is
   * sold should be supported.
   * @return the specified <code>TimeZone</code>, or null if the given ID
   * cannot be understood.
   */
  public synchronized TimeZone getInstance(String ID) {
    if (ID == null) {
      if (HOME_ID == null) {
        HOME_ID = System.getProperty("com.sun.cldc.util.j2me.TimeZoneImpl.timezone");
        if (HOME_ID == null)
          HOME_ID = "UTC";
      }
      ID = HOME_ID;
    }
    for (int i = 0; i < zones.length; i++)
      if (zones[i].getID().equals(ID))
        return zones[i];
    return null;
  }

  /** Gets all the available IDs supported.
   * @return  an array of IDs.
   */
  public synchronized String[] getIDs() {
    if (ids == null) {
      ids = new String[zones.length];
      for (int i = 0; i < zones.length; i++)
        ids[i] = zones[i].getID();
    }
    return ids;
  }

  // =======================privates===============================

  /**
   * The string identifier of this <code>TimeZone</code>.  This is a
   * programmatic identifier used internally to look up <code>TimeZone</code>
   * objects from the system table and also to map them to their localized
   * display names.  <code>ID</code> values are unique in the system
   * table but may not be for dynamically created zones.
   * @serial
   */
  private String ID;

  static String[] ids = null;

  /**
   * The month in which daylight savings time starts.  This value must be
   * between <code>Calendar.JANUARY</code> and
   * <code>Calendar.DECEMBER</code> inclusive.  This value must not equal
   * <code>endMonth</code>.
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int startMonth;

  /**
   * This field has two possible interpretations:
   * <dl>
   * <dt><code>startMode == DOW_IN_MONTH</code></dt>
   * <dd>
   * <code>startDay</code> indicates the day of the month of
   * <code>startMonth</code> on which daylight
   * savings time starts, from 1 to 28, 30, or 31, depending on the
   * <code>startMonth</code>.
   * </dd>
   * <dt><code>startMode != DOW_IN_MONTH</code></dt>
   * <dd>
   * <code>startDay</code> indicates which <code>startDayOfWeek</code> in th
   * month <code>startMonth</code> daylight
   * savings time starts on.  For example, a value of +1 and a
   * <code>startDayOfWeek</code> of <code>Calendar.SUNDAY</code> indicates the
   * first Sunday of <code>startMonth</code>.  Likewise, +2 would indicate the
   * second Sunday, and -1 the last Sunday.  A value of 0 is illegal.
   * </dd>
   * </ul>
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int startDay;

  /**
   * The day of the week on which daylight savings time starts.  This value
   * must be between <code>Calendar.SUNDAY</code> and
   * <code>Calendar.SATURDAY</code> inclusive.
   * <p>If <code>useDaylight</code> is false or
   * <code>startMode == DAY_OF_MONTH</code>, this value is ignored.
   * @serial
   */
  private int startDayOfWeek;

  /**
   * The time in milliseconds after midnight at which daylight savings
   * time starts.  This value is expressed as <em>wall time</em>, which means
   * it is compared to <em>standard</em> time for the daylight savings start.
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int startTime;

  /**
   * The month in which daylight savings time ends.  This value must be
   * between <code>Calendar.JANUARY</code> and
   * <code>Calendar.UNDECIMBER</code>.  This value must not equal
   * <code>startMonth</code>.
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int endMonth;

  /**
   * This field has two possible interpretations:
   * <dl>
   * <dt><code>endMode == DOW_IN_MONTH</code></dt>
   * <dd>
   * <code>endDay</code> indicates the day of the month of
   * <code>endMonth</code> on which daylight
   * savings time ends, from 1 to 28, 30, or 31, depending on the
   * <code>endMonth</code>.
   * </dd>
   * <dt><code>endMode != DOW_IN_MONTH</code></dt>
   * <dd>
   * <code>endDay</code> indicates which <code>endDayOfWeek</code> in th
   * month <code>endMonth</code> daylight
   * savings time ends on.  For example, a value of +1 and a
   * <code>endDayOfWeek</code> of <code>Calendar.SUNDAY</code> indicates the
   * first Sunday of <code>endMonth</code>.  Likewise, +2 would indicate the
   * second Sunday, and -1 the last Sunday.  A value of 0 is illegal.
   * </dd>
   * </ul>
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int endDay;

  /**
   * The day of the week on which daylight savings time ends.  This value
   * must be between <code>Calendar.SUNDAY</code> and
   * <code>Calendar.SATURDAY</code> inclusive.
   * <p>If <code>useDaylight</code> is false or
   * <code>endMode == DAY_OF_MONTH</code>, this value is ignored.
   * @serial
   */
  private int endDayOfWeek;

  /**
   * The time in milliseconds after midnight at which daylight savings
   * time ends.  This value is expressed as <em>wall time</em>, which means
   * it is compared to <em>daylight</em> time for the daylight savings end.
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int endTime;

  /**
   * The year in which daylight savings time is first observed.  This is an AD
   * value.  If this value is less than 1 then daylight savings is observed
   * for all AD years.
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   */
  private int startYear;

  /**
   * The offset in milliseconds between this zone and GMT.  Negative offsets
   * are to the west of Greenwich.  To obtain local <em>standard</em> time,
   * add the offset to GMT time.  To obtain local wall time it may also be
   * necessary to add <code>dstSavings</code>.
   * @serial
   */
  private int rawOffset;

  /**
   * A boolean value which is true if and only if this zone uses daylight
   * savings time.  If this value is false, several other fields are ignored.
   * @serial
   */
  private boolean useDaylight=false; // indicate if this time zone uses DST

  private static final int millisPerHour = 60*60*1000;
  private static final int millisPerDay  = 24*millisPerHour;

  /**
   * This field was serialized in JDK 1.1, so we have to keep it that way
   * to maintain serialization compatibility. However, there's no need to
   * recreate the array each time we create a new time zone.
   * @serial An array of bytes containing the values {31, 28, 31, 30, 31, 30,
   * 31, 31, 30, 31, 30, 31}.  This is ignored as of JDK 1.2, however, it must
   * be streamed out for compatibility with JDK 1.1.
   */
  private final byte monthLength[] = staticMonthLength;
  private final static byte staticMonthLength[] = {31,29,31,30,31,30,31,31,30,31,30,31}; //**NS**

  /**
   * Variables specifying the mode of the start rule.  Takes the following
   * values:
   * <dl>
   * <dt><code>DOM_MODE</code></dt>
   * <dd>
   * Exact day of week; e.g., March 1.
   * </dd>
   * <dt><code>DOW_IN_MONTH_MODE</code></dt>
   * <dd>
   * Day of week in month; e.g., last Sunday in March.
   * </dd>
   * <dt><code>DOW_GE_DOM_MODE</code></dt>
   * <dd>
   * Day of week after day of month; e.g., Sunday on or after March 15.
   * </dd>
   * <dt><code>DOW_LE_DOM_MODE</code></dt>
   * <dd>
   * Day of week before day of month; e.g., Sunday on or before March 15.
   * </dd>
   * </dl>
   * The setting of this field affects the interpretation of the
   * <code>startDay</code> field.
   * <p>If <code>useDaylight</code> is false, this value is ignored.
   * @serial
   * @since JDK1.1.4
   */
  private int startMode;

  /**
   * Variables specifying the mode of the end rule.  Takes the following